CO2 and Er:YAG laser systems can be used for ablative skin resurfacing. The ablative CO2 and Er:YAG technologies promote epidermal regeneration and collagen remodeling by removal of the epidermis accompanied by dermal contraction and remodeling. The CO2 laser produces thermal damage extending from 70 to 180 um into the dermis. However, because of high morbidity, significant down time and prolonged recovery period, they have decreased in popularity.
Non-ablative procedures were developed to minimize adverse effect and down time. These technologies protect the epidermis from laser induced thermal injury and leave the outer skin layer intact, typically through aggressive skin cooling. Thermal injury occurs at the deeper dermal structures to induce a wound healing process and remodeling. For example, the 1540 nm wavelength Er:Glass laser produces a mean depth of injury of about 700 μm. However, some patients want more noticeable results with fewer treatments.